keep harping on about (someone or something)

To continue to discuss, mention, or gripe about someone or something in a very persistent and irritating manner. My roommate keeps harping on about all the irritating people she works with. I wish she would just find a different job already. He just kept harping on about his various achievements throughout the whole date. I don't think he asked me about myself once! I don't want to keep harping on about this issue, but I really need it to be resolved today.